The article is about drinking your own urine
Drinking someone else's is a different case entirely.
In a health case, body fluids are always treated as if they're infected.
If OP did this and got caught, he's going to be told things like "he ould get sick/you hope he doesn't get sick"
or you know, op could go the other route, shove stuff in the starfish's backpack, possibly make the two sick and kill them from infection but alright, i guess nobody else has pointed out the health issues of the other few options, because somehow now when i say something kinda disgusting im pointed out but throwing human stuff in some poor kid's backpack is okay right? especially the possibility of disease and even death in rare cases.